Detergent composition for use in cleaning pile fabrics

ABSTRACT

THE MONOLITHIUM, MONOSODIUM, AND MONOAMMONIUM N-LAUROYL GLUTAMATES AND ASPARTATES, AND THE DILUTHIUM, DISODIUM, AND DIAMMONIUM N-STEAROYL GLUTAMATES AND ASPARTATES ARE SUPERIOR DETERGENTS FOR CLEANING PILE FIBRICS SUCH AS CARPETS BECAUSE OF THEIR GOOD SULUBILITY INWATER AND THE STRONG FOAMING OF THEIR AQUEOUS SOLUTIONS. THEY LEAVE NON-STICKY, POWDERY RESIDUES WHICH ARE READILY REMOVED BY VACUUM CLEANING.

United States Patent 3,761,223 DETERGENT COMPOSITION FOR USE IN CLEANING PILE FABRICS Ryonosuke Yoshida and Itsutoshi Maeda, Kanagawa-ken, Hitoshi Akiba, Saitama-ken, and Yasunori Usuba, gokyo, Japan, assignors to Ajinomoto Co., Inc., Tokyo,

a an Nd Drawing. Filed May 28, 1971, Ser. No. 148,236 Claims priority, application Japan, June 1, 1970, 45/ 46,596 Int. Cl. Clld 3/32 US. Cl. 8-137 4 Claims ABSTRACT OF THE DISCLOSURE The monolithium, monosodium, and monoammonium N-lauroyl glutamates and aspartates, and the diluthium, disodium, and diammonium N-stearoyl glutamates and aspartates are superior detergents for cleaning pile fabrics such as carpets because of their good solubility in water and the strong foaming of their aqueous solutions. They leave non-sticky, powdery residues which are readily removed by vacuum cleaning.

The present invention relates to a detergent composition suitable for use in the cleaning of pile fabrics such as carpets, rugs, upholstery, tapestries, cushion and other fabric coverings for floors, walls and furniture.

For removal of the dirt and soil which are present in such pile fabrics, the pile fabrics have been treated by dry-cleaning or by wiping with a floor-cloth wetted with a detergent solution.

However, dry-cleaning is not suitable for cleaning rugs or carpets since it is very difiicult to wash them wholly unlike the cleaning of clothes. And hence, the cleaning of rugs or carpets has been achieved by a method in which a detergent solution is applied to the surface of the fabrics to be cleaned and the fabrics are brushed to produce a rich foam, thereupon the dirt and soil are 00- cluded in the foam, and thereafter the foam is wiped off or sucked up.

When treated by this method, the fabrics are clean in appearance but the residue of detergent material leaves a sticky or oily deposit which would accelerate resoiling. Several attempts have been made to solve this problem, e.g. by adding to a detergent solution finely divided siliceous materials (US. Pat. No. 3,206,408 (1965)), or by adding a polymer emulsion which is capable of drying to powdery form (South African Pat. No. 6,704,138 (1968)). However, each of these methods has a fault that the presence of such additives induces the lowering of foaming power. Also, the use of siliceous material tends to impair the elasticity of the fabrics. An alkali salt of higher alkyl sulphate, alkali salt of N-higher acyl sarcosinate or their mixtures (British Pat. No. 882,635 (1958)) and a lithium salt of higher alkyl sulphate have been employed as detergents (British Pat. No. 1,027,154 (1962)). Although all of these detergents can be applied as aqueous solutions and may foam powdery particles after the evaporation of water, the formed powdery particles turn into a sticky deposit owing to their ice tion for pile fabrics containing one or more of the mono-' lithium, monosodium and monoammonium salts of N- lauroyl acidic amino acids and dilithium, disodium and diammonium salts of N-stearoyl acidic amino acids.

Only these salts have good water solubility, high foaming power and good foam retaining properties on all kinds of natural or synthetic fabrics to be cleaned and they are capable of drying to a substantially non-sticky powdery deposit on fabrics.

In order to clean the soiled pile fabrics with the detergent composition of the present invention, therefore, said detergent composition is dissolved in water and the resulting aqueous solution is applied to the surface of the fabrics to be cleaned by suitable means. Thereafter, by moving a brushing appliance backwards and forwards on the fabrics, rich foams are produced. The dirt and water soluble or oily soil are loosened and occluded in the foam, and then the produced foams are wiped off or sucked up to achieve the cleaning purpose. After the evaporation of water, the detergent of the present invention forms a crystalline non-sticky deposit on the fabrics, which deposit can be readily removed by use of a vacuum cleaner, a sweeper or some similar equipment. Therefore, the cleaning of the pile fabrics may be conveniently achieved without removing them from their usual position. Also, the detergent of the present invention gives high brightness and smoothness to the cleaned fabrics without impairing their elasticity.

Similar salts such as potassium and triethanolamine salts of N-lauroyl or N-stearoyl acidic amino acids become very sticky in their dry state. Also, the corresponding dialkali metal salts of N-lauroyl acidic amino acid and the corresponding monoalkali metal salts of N-stearoyl acidic amino acids are not entirely suitable for this purpose for the reasons that some of them are hardly soluble in water and the water-soluble ones are deficient in foaming property. Furthermore, the similar alkali metal salts of N-acyl acidic amino acids having acyl groups other than lauroyl and stearoyl groups, such as N-myristoyl or N-palmytoyl, are not suitable as detergents for pile fabrics because the monoalkali metal salts are hardly soluble in water while the dialkali metal salts are soluble in water but are deficient in foaming property.

The results of tests of various N-acyl acidic amino acid salts for use in the cleaning of pile fabrics are summarized in Table 1 which also shows the results of tests carired out similarly with respect to the hitherto known detergents, sodium dodecyl sulphate (SDS), sodium N-lauroyl sarcosinate (L-Sar.), lithium lauryl sulphate (LLS), and a mixture of lithium lauryl sulphate and lithium decyl sulphate (a product of Cyclo Chemicals Ltd., referred to as Cyclo) for comparison.

It will be seen from Table 1 that the monolithium, monosodium .and monoammonium salts of N-lauroyl acidic amino acids and the dilithium, disodium and diammonium salts of N-stearoyl acidic amino acids of the present invention have good water solubility and good foaming power that are comparable to the commercially available control samples and are markedly superior to the control samples with respect to non-stickiness of the powdery particles formed when a detergent solution was evaporated to dryness. Also, detergent solutions for cleaning pile fabrics are required to permeate the fabrics as little as possible, unlike the detergent materials for use in cleaning clothes. In view of this point, dilithium, disodium and diammonium salts of N-stearoyl acidic amino acids are superior compared with the control samples.

EXAMPLE 2 2.9 kg. of the diammonium salt of N-hydrogenated tollowyl L-glutamic acid and 0.7 'kg. of ditriethanolamine salt of N-cocoyl** L-glutamic acid were dissolved in water to prepare 18 l. of detergent solution. This solution was diluted with water to about 1% and then used to treat soiled carpets as in Example 1. The carpets were allowed to dry, the powdery deposit retained on the carpets was less sticky than a deposit of a control sample, and removed completely by a vacuum cleaner.

The carpets treated so were clean.

EXAMPLE 3 EXAMPLE 4 125 g. of monosodium N-lauroyl-L-aspartate and 75 g. of monolithium N-lauroyl-DL-aspartate were dissolved in water to prepare 1 l. of solution. The solution was diluted with water to 1%. Soiled carpets were treated with this solution in the same manner as in Example 3. After drying, the residue of detergent retained on the carpets was non-sticky and in powdery form and was easily removed by a vacuum cleaner. The carpets treated thus were well cleaned with brightness and softness.

EXAMPLE 5 A mixture of 100 g. of monolithium N-distilled cocoyl- L-glutamate, 90 g. of dilithium N-distilled cocoyl-L-glutamate and g. of lithium lauryl sulphate was dissolved in water to prepare 1 l. of solutidn. The solution was diluted with Water to 1% and then applied to the soiled carpets as in Example 3. After drying, the powdery detergent retained on the carpets was good and the carpets became clean.

EXAMPLE 6 A mixture of 200 g. of diammonium N-semi-hydrogenated tallowyl-L-glutamate, g. of sodium-DL-alanimate and g. of triethanolamine salt of lauryl sulphuric acid was dissolved in water to prepare 1 l. of solution. The solution was diluted with water to 1% and then apthe carpet became clean.

Hydrogenated tallowyl means acyl residue of hydrogenated tallow fatty acid.

*Cocoyl means the acyl residue of coconut oil fatty acid.

6 EXAMPLE 1 g. of disodium N-stearoyl-DL-aspartate and 50 g. of monosodium N-stearoyl-DL-aspartate were dissolved in water to prepare 1 l. of solution, which was diluted with water to 1%.

The soiled carpet was treated with the solution as in Example 3. The carpet cleaned had a luster and became clean.

EXAMPLE 8 30 kg. of powdery monosodium N-cocoyl-L-glutamate was mixed with 0.6 kg. of powdery sodium lauryl sulphate and the mixture was dissolved in warm water of 40 C. to prepare 150 1. solution. The solution was diluted with water to 1%, and then the soiled carpet was treated with the solution according to the same manner as in Example 1. The carpet was allowed to dry and the powdery state of detergent retained on the carpet was good. The carpet became clean.

What we claim is:

1. A method of cleaning a fabric of soil which comprises applying to said fabric a foam of an aqueous solution of a monoalkali metal or monoammonium salt of N-lauroyl glutamate or N-lauroyl aspartate, or of a dialkali metal or diammonium salt of N-stearoyl glutamate or N-stearoyl aspartate, the alkali metal in said salts being lithium or sodium, the amount of said foam being sufficient to occlude said soil, and thereafter removing said foam from said fabric.

2. A method as set forth in claim 1, wherein said aqueous solution is applied to said fabric and thereafter converted to said foam by brushing said fabric.

3. A method as set forth in claim 2, wherein said foam, prior to said removing, is permitted to dry on said fabric.

4. A method as set forth in claim 3, wherein said fabric is a pile fabric.

References Eited UNITED STATES PATENTS 3,630,919 12/1971 Sheaffer et a1. -l 8-137 X 3,401,007 9/1968 Hoffman et al 8-137 2,320,281 5/1943 Kalusdian 8-137 2,047,069 7/1936 Hentrich et a1 252-356 X FOREIGN PATENTS 546,942 3/ 1932 Germany 260-404 HERBERT B. GUYNN, Primary Examiner US. Cl. X.R. 252-544 

